1. Field of the Invention
The present invention relates to methods and means for effecting protection of humans from the deleterious effects of airborne asbestos and other particulate contamination and involves the use of several specially designed, partially or wholly transparent cowling means operatively associated with drilling and/or sawing means. The first and second of three such cowling means are operatively associated with at least one filtration unit flow connected therewith and with a blower to pull air into the specially designed cowlings and thence into the filtration unit wherefrom the resulting filtered air is exhausted to the atmosphere. In order to accommodate the travel of the drill bit, the first cowling means operatively associated with said drilling means comprises two members slidably disposed relative to one another, with the first member thereof being more or less substantially fixed relative to the drill housing and the second member adapted to be fitted temporarily to the target side of the mounting board or other member to be drilled. In the preferred embodiment of the instant invention, said second member of said first cowling means is provided with means for effecting the flow connection with said at least one filtration unit. Normally, a second cowling means, also flow connected to said filtration unit, is operatively associated with the instant apparatus and is fitted temporarily (usually hand held by the operator or helper) to the side of the material which is opposite to that first targeted for engagement with the drill bit of said drilling means. A third cowling means, also flow connected to said filtration unit, is operatively associated with sawing or cutting means, which sawing means may be utilized after holes are drilled in the mounting board to cut therebetween. The third cowling means is generally fixed relative to the housing of said saw. One end of said third cowling means is open and adapted to fit over the base plate of the saw, normally of the saber type, and the aperture represented by said open end defines a plane substantially parallel with the plane of the target board. Likewise, one end of the second cowling is generally open ended, with the plane defined by said aperture or open end, also disposed generally parallel with such board. It is important that all three cowlings be constructed of material that is stiff, and/or resilient enough to withstand the substantial pressures that may be developed therearound due to the pressure differential developed by operation of the associated filtration unit. It is also important to the efficient and effective operation of the instant invention that all three such cowling members or units be at least partially constructed of material which is transparent, thereby enabling the drill or saw operator to observe the positions of either the drill bit or saw blade relative to the target and to enable such operator to easily and readily effect proper orientation and/or positioning therebetween. It will also be appreciated that provisions may be made such that the flow connections with the at least one filtration unit and the first and third cowling means are arranged or constructed such that they are, or can be releasably connected therewith. In such manner, after the holes are drilled and the drill is put aside, the vacuum hose connected to the second member of the first cowling means, may be removed therefrom and connected, with the aid of suitable connecting means, to said third cowling means. Also, in the preferred embodiment of the instant invention the second cowling means and the vacuum hose operatively associated therewith, which is normally used on the backside of the board or plate to be drilled and/or sawed to capture particulate material forced therethrough by either the bit or blade, is utilized in separate combinations with either the drill or the saw. Accordingly, the usually is no need to effect a disconnection between said second cowling means and said at least one filtration unit. Thus, either three separate vacuum hoses may be used, or more preferably two vacuum hoses are utilized with a switching between the first and third cowling means being effected by releasable connecting means, if and when it is deemed desirable to follow the drilling procedure with a sawing operation. As will also be seen, two or more subhoses may be utilized to connect with said third cowling means and thence to a manifold or like device to join in flow connection with the other hose(s), usually via a trunk line, to the filtration unit.
2. Description of the Prior Art
As has been noted above, numerous prior art disclosures and practices have been incorporated into currently used procedures representing many of those taught and disclosed in a plethora of methods and/or means for ameliorating the deleterious health and personal safety considerations normally encountered in the removal and/or modification of structures or substructures constructed of materials comprising or containing asbestos or other highly friable materials which are classified as being, or presenting a carcinogenic hazard to humans.
With reference to the state of the prior art as same relates to the utilization of numerous tent-like enclosures erected or otherwise constructed over and about work areas within which asbestos, or asbestos containing materials are to be drilled, sawed, or otherwise machined, and more specifically to the utilization of negative pressures in combination therewith, and still more particularly to various modifications thereof in combination with a variety of specially designed ingress/egress aperture closure means, attention is directed to U.S. Pat. No. 4,604,111, Natale, Aug. 5, 1986, the teachings of which, along with the prior art disclosed therein, are hereby, herewith, and herein incorporated by means of this specific reference thereto.
A comparison of such prior art teachings with the disclosure of the instant invention will reveal that the instant improvement over same completely eliminates the requirement or necessity of utilizing a tent or like structure to be erected over or about the work area when asbestos type materials are to be drilled, sawed, or otherwise machined. Perhaps of equal importance, the practice of the instant invention eliminates the requirement for wearing or the necessity of utilizing full suit protective clothing and in-line respiratory devices in such work areas during the conduct of such operations.